android ZLib压缩/解压缩

项目里面有一个接口要频繁的刷新数据，同时数据量有很大，为了优化传输速度和节省流量，决定使用传输二进制数据，并将数据进行ZLib压缩。这就需要APP端进行二进制数据的解析和对数据进行ZLib解压缩.

不多说了，具体代码如下:

//把文件转换成byte[]数组

	//把文件转换成byte[]数组
	byte[] bytes0 = FileUtils.toByteArray(getExternalFilesDir(null).getPath()
        	+ File.separator+byteImgName);
	//ZLib解压缩数据
	byte[] bytes = ZLibUtils.decompress(bytes0);

  

FileUtils:

public class FileUtils{
    /** 
      * the traditional io way  
      * @param filename 
      * @return 
      * @throws IOException 
      */
    public static byte[] toByteArray0(String filename) throws IOException{

        File f = new File(filename);
        if(!f.exists()){
        throw new FileNotFoundException(filename);}

        ByteArrayOutputStream bos = new ByteArrayOutputStream((int)f.length());
        BufferedInputStream in = null;
        try{
            in = new BufferedInputStream(new FileInputStream(f));
            int buf_size = 1024;
            byte[] buffer = new byte[buf_size];
            int len = 0;
            while(-1 != (len = in.read(buffer,0,buf_size))){
                bos.write(buffer,0,len);
            }
            return bos.toByteArray();
         }catch (IOException e) {
            e.printStackTrace();
            throw e;
        }finally{
            try{
                in.close();
            }catch(IOException e){
                 e.printStackTrace();
            }
            bos.close();
        }
    }

    /**
     * NIO way
     * @param filename
     * @return
     * @throws IOException
     */
    public static byte[] toByteArray2(String filename)throws IOException{

        File f = new File(filename);
        if(!f.exists()){
            throw new FileNotFoundException(filename);
        }

        FileChannel channel = null;
        FileInputStream fs = null;
        try{
            fs = new FileInputStream(f);
            channel = fs.getChannel();
            ByteBuffer byteBuffer = ByteBuffer.allocate((int)channel.size());
            while((channel.read(byteBuffer)) > 0){
                // do nothing
                MyTrace.e("reading");
            }
            return byteBuffer.array();
        }catch (IOException e) {
            e.printStackTrace();
            throw e;
        }finally{
            try{
                channel.close();
            }catch (IOException e) {
                e.printStackTrace();
            }
            try{
                fs.close();
            }catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


    /**
     * Mapped File  way
     * MappedByteBuffer 可以在处理大文件时，提升性能
     * @param filename
     * @return
     * @throws IOException
     */
    public static byte[] toByteArray(String filename)throws IOException{

        FileChannel fc = null;
        try{
            fc = new RandomAccessFile(filename,"r").getChannel();
            MappedByteBuffer byteBuffer = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size()).load();
            System.out.println(byteBuffer.isLoaded());
            byte[] result = new byte[(int)fc.size()];
            if (byteBuffer.remaining() > 0) {
                MyTrace.e("remain");
                byteBuffer.get(result, 0, byteBuffer.remaining());
            }
            return result;
        }catch (IOException e) {
            e.printStackTrace();
            throw e;
        }finally{
            try{
                fc.close();
            }catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


}

ZLibUtils:

public class ZLibUtils {

    /**
     * 压缩
     *
     * @param data 待压缩数据
     * @return byte[] 压缩后的数据
     */
    public static byte[] compress(byte[] data) {
        byte[] output = new byte[0];

        Deflater compresser = new Deflater();

        compresser.reset();
        compresser.setInput(data);
        compresser.finish();
        ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length);
        try {
            byte[] buf = new byte[1024];
            while (!compresser.finished()) {
                int i = compresser.deflate(buf);
                bos.write(buf, 0, i);
            }
            output = bos.toByteArray();
        } catch (Exception e) {
            output = data;
            e.printStackTrace();
        } finally {
            try {
                bos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        compresser.end();
        return output;
    }

    /**
     * 压缩
     *
     * @param data
     *            待压缩数据
     *
     * @param os
     *            输出流
     */
    public static void compress(byte[] data, OutputStream os) {
        DeflaterOutputStream dos = new DeflaterOutputStream(os);

        try {
            dos.write(data, 0, data.length);

            dos.finish();

            dos.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 解压缩
     *
     * @param data
     *            待压缩的数据
     * @return byte[] 解压缩后的数据
     */
    public static byte[] decompress(byte[] data) {
        byte[] output = new byte[0];

        Inflater decompresser = new Inflater();
        decompresser.reset();
        decompresser.setInput(data);

        ByteArrayOutputStream o = new ByteArrayOutputStream(data.length);
        try {
            byte[] buf = new byte[1024];
            while (!decompresser.finished()) {
                int i = decompresser.inflate(buf);
                o.write(buf, 0, i);
            }
            output = o.toByteArray();
        } catch (Exception e) {
            output = data;
            e.printStackTrace();
        } finally {
            try {
                o.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        decompresser.end();
        return output;
    }

    /**
     * 解压缩
     *
     * @param is
     *            输入流
     * @return byte[] 解压缩后的数据
     */
    public static byte[] decompress(InputStream is) {
        InflaterInputStream iis = new InflaterInputStream(is);
        ByteArrayOutputStream o = new ByteArrayOutputStream(1024);
        try {
            int i = 1024;
            byte[] buf = new byte[i];

            while ((i = iis.read(buf, 0, i)) > 0) {
                o.write(buf, 0, i);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
        return o.toByteArray();
    }


}